Epidermal responses of chum salmon (Oncorhynchus keta) fry to the ectoparasitic flagellate Ichthyobodo necator

1992 ◽  
Vol 70 (8) ◽  
pp. 1567-1575 ◽  
Author(s):  
Shigehiko Urawa
Keyword(s):  
Parasite Density ◽  
Chum Salmon ◽  
Periodic Acid ◽  
Mucous Cell ◽  
Major Constituent ◽  
Control Fish ◽  
Oncorhynchus Keta ◽  
Staining Procedure ◽  
Mucous Cells ◽  
Cell Secretion

The numbers of the ectoparasitic flagellate Ichthyobodo necator on chum salmon fry (Oncorhynchus keta) and the host's epidermal responses to infection were monitored for 15 weeks with light and scanning electron microscopy. Parasite density on the skin peaked at 3 weeks postinfection, at an average of 625 parasites/mm2, and then decreased to near zero by week 10. The staining procedure with Alcian blue (AB, pH 2.5) and periodic acid – Schiffs reagent (PAS) revealed dramatic changes in both the degree and histochemistry of epidermal mucus secretion during the course of the parasite infections. The numbers of mucous cells declined significantly during the first 4 weeks as parasite density increased, but thereafter rose to 2000 cells/mm2 by week 8, when mucous cells stained with PAS alone predominated. This increase occurred concomitantly with a reduction in parasite density. In the control fish, the concentration of epidermal mucous cells was stable at 400 – 800 cells/mm2 during the same period and acid mucopolysaccharides (PAS-negative, AB-positive) were a major constituent of the mucous cell secretion. It is suspected that the PAS-positive mucous cells may play an important role in the defence mechanism against the parasite infection.

DNA synthesis and Bcl-2 expression during development of mucous cell metaplasia in airway epithelium of rats exposed to LPS

2004 ◽  
Vol 286 (2) ◽  
pp. L268-L274 ◽  
Author(s):  
Yohannes Tesfaigzi ◽  
J. Foster Harris ◽  
Jon A. Hotchkiss ◽  
Jack R. Harkema
Keyword(s):  
Cell Cycle ◽  
Epithelial Cells ◽  
Basal Lamina ◽  
Periodic Acid ◽  
Mucous Cell ◽  
Airway Epithelial Cells ◽  
Regulatory Function ◽  
Secretory Cells ◽  
Mucous Cells ◽  
Proliferating Cells

Exposure of pulmonary airways to environmental toxins and allergens may cause proliferation of airway epithelial cells and mucous cell metaplasia (MCM); however, it is unclear to what extent proliferating cells differentiate into mucus-storing cells and contribute to MCM. Our previous studies demonstrated that Bcl-2, an inhibitor of apoptosis with cell cycle regulatory functions, is expressed in metaplastic mucous cells. The purpose of the present study was to investigate the number of metaplastic mucous cells that are derived from proliferating epithelial cells and whether Bcl-2 has a role in cell cycle entry in these cells. Rats were intratracheally instilled with 100 μg of LPS from Pseudomonas aeruginosa in 500 μl of saline, and proliferating airway cells were labeled with bromodeoxyuridine (BrdU) by implanting a subcutaneous osmotic pump 24 h before instillation. The volume of stored mucosubstance and the number of mucous cells were increased 10- and 3-fold, respectively, from 24–48 h after instillation. The number of total epithelial cells per millimeter of basal lamina increased, and the number of serous cells per millimeter of basal lamina decreased during this time. Approximately 50% of Alcian blue-periodic acid Schiff-stained mucous cells were labeled with BrdU at 48 h after instillation, suggesting that one-half of the secretory cells were derived from proliferating cells. Furthermore, 50% of the Bcl-2-positive mucous cells were BrdU negative and therefore derived from nonproliferating, preexisting cells. Our findings demonstrate that preexisting and proliferating cells differentiate into mucous cells and compose LPS-induced metaplasia and that Bcl-2 does not have cell cycle regulatory function in these cells.

Nature and Time Course of Acclimation to Aluminum in Juvenile Brook Trout (Salvelinus fontinalis). II. Gill Histology

1991 ◽  
Vol 48 (10) ◽  
pp. 2016-2027 ◽  
Author(s):  
M. E. Mueller ◽  
D. A. Sanchez ◽  
H. L. Bergman ◽  
D. G. McDonald ◽  
R. G. Rhem ◽  
...  
Keyword(s):  
Brook Trout ◽  
Time Course ◽  
Salvelinus Fontinalis ◽  
Mucous Cell ◽  
Volume Density ◽  
Cellular Level ◽  
Control Fish ◽  
Mortality Data ◽  
Mucous Cells ◽  
Exposed Fish

Gill samples from juvenile brook trout (Salvelinus fontinalis) acclimated to low-level aluminum at pH 5.2 showed severe damage by day 4, with necrosis and fusion of secondary lamellae and hyperplasia and hypertrophy of mucous cells. Over the following 20 d, there was a continual process of repair with proliferation and hypertrophy of mucous cells. Qualitative analysis of gill samples plus physiology and mortality data collected in a companion study indicated progressive development (by day 10 onward) of increasing acclimation to Al. Quantitative analysis of gill samples on day 13 showed that mucous cell volume density had tripled and mucous cell area had doubled in Al-exposed fish compared with control fish. A lamellar fusion index showed evidence of fusion in Al-exposed fish by day 4 with recovery to nearly control levels by day 13. Physiological disturbances appear to be directly related to the histological changes observed in the gill epithelium. At the cellular level, changes in either mucous cell production and secretion or changes in mucus chemistry contribute, in part, to acclimation to Al.

Proximal airway mucous cells of ovalbumin-sensitized and -challenged Brown Norway rats accumulate the neuropeptide calcitonin gene-related peptide

2004 ◽  
Vol 287 (2) ◽  
pp. L286-L295 ◽  
Author(s):  
Shawnessy D. Larson ◽  
Charles G. Plopper ◽  
Greg Baker ◽  
Brian K. Tarkington ◽  
Kendra C. Decile ◽  
...  
Keyword(s):  
Periodic Acid ◽  
Mucous Cell ◽  
Calcitonin Gene Related Peptide ◽  
Neuroendocrine Cells ◽  
Brown Norway ◽  
Mucous Cells ◽  
Periodic Acid Schiff ◽  
Related Peptide ◽  
Afferent Nerves ◽  
Calcitonin Gene

Mucous cell hypersecretion and increased neuropeptide production play a role in the exacerbation of symptoms associated with asthma. The source of these neuropeptides have been confined to the contributions of small afferent nerves or possibly neuroendocrine cells. We tested the hypothesis that repeated exposure to allergen would alter the sources and abundance of neuropeptides in airways. Right middle lobes from rats (8 wk old) exposed to 2.5% ovalbumin (OVA) for five episodes (30 min each) or filtered air were inflation fixed with paraformaldehyde. The lobes were dissected to expose the airway tree, permeabilized with DMSO, and incubated in antibody to rat calcitonin gene-related peptide (CGRP), followed with a fluorochrome-labeled second antibody. CGRP-positive structures were imaged via confocal microscopy. Airways were later embedded in plastic and sectioned for cell identification. In animals challenged with OVA, CGRP-positive cells, not neuroendocrine or neuronal in origin (confirmed by a lack of protein gene product 9.5 signal), were recorded along the axial path. In section, this fluorescent signal was localized to granules within epithelial cells. Alcian blue/periodic acid-Schiff staining of these same sections positively identify these cells as mucous cells. Mucous cells of animals not challenged with OVA were not positive for CGRP. We conclude that episodic allergen exposure results in the accumulation of CGRP within mucous cells, creating a new source for the release of this neuropeptide within the airway.

Effects of rearing conditions on growth and mortality of juvenile chum salmon (Oncorhynchus keta) infected with Ichthyobodo necator

1995 ◽  
Vol 52 (S1) ◽  
pp. 18-23 ◽  
Author(s):  
Shigehiko Urawa
Keyword(s):  
Water Supply ◽  
Parasite Density ◽  
Chum Salmon ◽  
Stocking Density ◽  
Total Mortality ◽  
Oncorhynchus Keta ◽  
Growth And Survival ◽  
Chum Salmon Oncorhynchus Keta ◽  
Host Growth ◽  
Seawater Challenge

Chum salmon (Oncorhynchus keta) juveniles, experimentally infected with the bodonid flagellate Ichthyobodo necator (Henneguy, 1883), were reared in 18-L tanks at three densities (300, 600, and 1200 fish) for 5 weeks. Water inflow rates were adjusted to give five combinations of crowding and flow rate. The parasite density on the fish body surface increased to 2700–4100 parasites-mm−2 over the course of the experiment and did not differ significantly among the groups. Total mortality was 76–90% in infected groups kept under the most unfavorable conditions (crowding or low water supply) but 11–15% in the other infected groups. The former groups also showed apparent growth reductions. In the uninfected controls, mortality was low (0.7–2.6%) and the degree of crowding or water supply had no significant effect on growth or mortality. Infected salmon were also much less resistant to seawater challenge; all fish kept at high stocking density or low inflow rate died in seawater. These results indicate that Ichthyobodo infections have marked effects on both host growth and survival when infections are combined with environmental stress induced by overcrowding and (or) inadequate water supply, although the parasite density is not affected by these factors.

scholarly journals Role for Mucin-5AC in Upper and Lower Airway Pathogenesis in Mice

2021 ◽  
pp. 019262332110044
Author(s):  
Hye-Youn Cho ◽  
Soojung Park ◽  
Laura Miller ◽  
Huei-Chen Lee ◽  
Robert Langenbach ◽  
...  
Keyword(s):  
Periodic Acid ◽  
Mucous Cell ◽  
Ozone Exposure ◽  
Lower Airway ◽  
Periodic Acid Schiff ◽  
Nasal Airways ◽  
Airway Injury ◽  
Syncytial Virus ◽  
Syncytia Formation ◽  
Injury Protection

Mucin-5AC (MUC5AC) is a major secreted mucin in pathogenic airways. To determine its role in mucus-related airway disorders, Muc5ac-deficient ( Muc5ac−/−) and wild-type ( Muc5ac+/+) mice were compared in bleomycin-induced pulmonary fibrosis, respiratory syncytial virus (RSV) disease, and ozone toxicity. Significantly greater inflammation and fibrosis by bleomycin were developed in Muc5ac−/− lungs compared to Muc5ac+/+ lungs. More severe mucous cell metaplasia in fibrotic Muc5ac−/− lungs coincided with bronchial Muc2, Muc4, and Muc5b overexpression. Airway RSV replication was higher in Muc5ac−/− than in Muc5ac+/+ during early infection. RSV-caused pulmonary epithelial death, bronchial smooth muscle thickening, and syncytia formation were more severe in Muc5ac−/− compared to Muc5ac+/+. Nasal septal damage and subepithelial mucoserous gland enrichment by RSV were greater in Muc5ac−/− than in Muc5ac+/+. Ozone exposure developed more severe nasal airway injury accompanying submucosal gland hyperplasia and pulmonary proliferation in Muc5ac−/− than in Muc5ac+/+. Ozone caused periodic acid-Schiff-positive secretion only in Muc5ac−/− nasal airways. Lung E-cadherin level was relatively lower in Muc5ac−/− than in Muc5ac+/+ basally and after bleomycin, RSV, and ozone exposure. Results indicate that MUC5AC is an essential mucosal component in acute phase airway injury protection. Subepithelial gland hyperplasia and adaptive increase of other epithelial mucins may compensate airway defense in Muc5ac−/− mice.

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